1. Field of the Invention
The present invention generally relates to electronically controlled actuators and methods used to configure electronically controlled actuators.
2. Description of the Known Technology
Automobiles are equipped with electronically controlled actuators for opening and closing of passageway door located throughout the automobile. These passageways may include heating, ventilation and air conditioning passageways or passageways for the intake manifolds of the vehicle's internal combustion engine. The actuators open and close doors in the passageways by rotating a shaft connected to the door. To do this, a controller that determines if the shaft has rotated the door to a fully opened or fully closed position by monitoring the output of a Hall Effect sensor. The Hall Effect sensor is able to determine the position of the shaft via a magnet is coupled to the shaft. As a shaft moves, so does the magnet, thereby varying the magnetic field about by the Hall Effect sensor. When the output of the Hall Effect sensor is a specific value indicating that the shaft has rotated the door to a fully opened or fully closed position, the controller will instruct the actuator to stop rotating the shaft.
Some Hall Effect sensors are programmable. Programmable Hall Effect sensors can be programmed to output a specific value when receiving a specific magnetic field. For example, a programmable Hall Effect sensor may be programmed to output the value X when the programmable Hall Effect sensor receives a magnetic field indicating that the actuator has fully opened the door and output the value Y when the programmable Hall Effect sensor receives a magnetic field indicating that the actuator has fully closed the door. This allows the controller to monitor for the specific values, X and Y, when determining if the actuator has rotated the door to a fully opened or fully closed position.
However, there are certain drawbacks to using programmable Hall Effect sensors. First, programmable Hall Effect sensors are more costly than non-programmable Hall Effect sensors. Second, in order to program a programmable Hall Effect sensor, one must be able to physically access a programming input port located on the programmable Hall Effect sensor. However, the programming input port is only accessible when the actuator is disassembled or additional connector pins are provided. Therefore, programmable Hall Effect sensors must be programmed when the actuator is disassembled. Upon assembly of the actuator, the distance between the magnet and the programmable Hall Effect sensor may change and may be different from that anticipated during programming. This change in distance will change the magnetic field received by the programmable Hall Effect sensor. In turn, the change in the amount of magnetic field received by the Hall Effect sensor will adversely affect the output of the programmable Hall Effect sensor and the accuracy of the system.
Therefore, there is exists a need for a cost effective solution that allows the controller to accurately determine when the actuator has moved the door to a fully opened or fully closed position.